1. Field of the Invention.
The present invention relates to the field of controlled flow, exhaust manifold systems and, more particularly, to apparatus for controlling the flow of exhaust gases between a plurality of rocket storage and launch stations and a common exhaust gas manifold or plenum tube connected thereto.
2. Description of the prior art.
In certain military applications, particularly on warships having missile firing capability, the missiles are stored in a series of vertically oriented chambers closely adjacent one another. Exhaust gas outlets are normally provided to duct rocket exhaust gases generated during intended or accidental rocket ignitions to a safe location. In such installations, manifolding of a number of chambers into a common exhaust duct or plenum tube is often necessary.
There have been a number of approaches to the problems attendant upon the use of a common exhaust duct with a number of missile storage chambers. It is important to be able to block the exhaust gases from a missile which is being fired from blowing out the individual chambers of other missiles. This is commonly accomplished by the use of doors or hinged panels which can open from the force of an impinging missile exhaust for the chamber in which the missile being fired is located and close off the passage at the base of a missile chamber opening into the exhaust plenum for other missiles.
Whereas individual storage and launch chambers for missiles are generally round in cross-section, it will be understood that in the utilization herein in which the chambers are mounted side by side and closely adjacent one another, the chambers are constructed with a generally square cross-section for convenience and to minimize the space required to accommodate such an installation on board ship, for example. Where the rectangular cross-section is extended below the missile chamber and into the plenum, there is a likelihood that the plenum gases will flow back into the missile chamber through the residual cross-sectional area formed between the naturally circular exhaust flow from the rocket nozzle and the corners of the rectangular cross-section of the transition section. Such recirculation of plenum gas flow into the missile chamber is undesirable from the standpoint of both heat transfer as well as contaminaton.
The Spurk U.S. Pat. Nos. 3,324,534 and 3,421,781 are directed to the fabrication of a transition section between a round pipe and a pipe of the same cross-sectional area but of different shape. The transition section is also designed to provide the same cross-sectional area as the passages to which it is connected. This apparatus is principally intended for use in test chambers, such as shock tubes, supersonic flow passages, expansion tubes and the like. In contradistinction thereto, the present invention relates to a transitional section from a rocket or missile container of rectangular cross-section to a circular cross-section opening into a common plenum which channels the exhaust gases to a safe location. The circular opening is normally smaller in cross-sectional area than the rectangular opening.
British Pat. No. 720,206 describes a transition section for sheet metal duct work which changes from round to square and back to round in order to increase the cross-sectional area in the transition section, thereby permitting sharper bends to be achieved with less flow resistance. The Warren U.S. Pat. No. 3,552,780 similarly discloses a transition section connector between rectangular and circular conduits for use with gutter downspouts, principally for esthetic purposes. The Anderson U.S. Pat. No. 3,014,410 and the Little U.S. Pat. No. 2,802,399 disclose arrangements for deflecting and diverting exhaust gases from a missile, but do not involve the use of a common gas manifold or plenum tube connected thereto.